1. Field of the Invention
One or more embodiments of the invention relate to compositions and method for synthesizing the navel orangeworm pheromones and methods for using thereof for pest management.
2. Description of the Related Art
As the need for food production in the world grows so does the need for new forms of pest control. The increasing use of conventional pesticides leads to resistant pests, severely alters the natural ecology, and damages the environment. This problem has led to innovative ways in pest management without the use of pesticides. One of the ways that has been presented is the use of insect sex pheromones (Shani, A., “Integrated pest management using pheromones,” Chemtech 28(3), pp. 30-35 (1998)).
Sex pheromones are used in the chemical communication of many insects for attracting the species of the opposite sex to engage in reproduction. Pheromones are useful for pest control largely through four means: monitoring, mass trappings, attract and kill, and disruption of communication or confusion. “Monitoring” methodology attracts the pests to a central area, which allows the grower to obtain precise information on the size of the pest population in order to make informed decisions on pesticide use or non-use. “Mass trappings” brings the pest to a common area and physically trap them, which hinder production of new generations of pests. “Attract and kill” allows the pests to be drawn into a centrally located container and killed in the container by the pesticide reducing the need to spread pesticides in broad areas. “Disruption of communication” can occur in that a large concentration of sex pheromone can mask naturally occurring pheromones or saturate the receptors in the insect causing confusion and disruption of natural reproductive means (Shani, 1998). For each one of these means, each individual species of pest needs to be treated with a tailor-made composition which can add substantially to the cost in creating a bulk amount.
Pheromones are considered relatively non-toxic, not environmentally persistent (decompose quickly in nature), and do not create resistance by pests. These qualities make them a superior choice as an alternative to pesticides. Because of the need for more environmentally friendly pest management, the industry has emphasis to develop more efficient and cost-effective production methods for the pheromones while utilizing more environmentally benign methods for their production.
One of the more pervasive pests in agriculture areas of tree-nut production is the larval worm of the moth family Lepidoptera: class Pyralidae known as the Navel Orangeworm, Amyelosis transitella. The tree-nut industry is a multi-billion dollar industry but estimates show only 1% of the cultivated land uses pheromones for pest control (Shani, 1998). With a relatively high cost for producing the pheromones, the economic impact creates a strong need to create an efficient method to produce the sex pheromone of the navel orangeworm.
One of the major sex pheromone of the navel orangeworm has been isolated and analyzed is (Z,Z)-11,13-hexadecadienal (HDAL). This pheromone and others have been described in studies and belongs in the Ando type I pheromones (Ando T. et al., “Lepidopteran sex pheromones,” Top Curr Chem 239: 51-96, 2004). HDAL has been shown in other studies to have a high affinity for binding to a major pheromone binding protein (AtraPBP) which can correlate to having some effect on the mating disruption and monitoring of the adult moths (Leal et al., “Unusual pheromone chemistry in the navel orangeworm: novel sex attractants and a behavioral antagonist,” Naturewissenshaften 92:139-146 (2005)).
A method of synthesis for HDAL was described in a 1980 publication that described an at least seven step method (Sonnett, P. E. and R. R. Heath, “Stereospecific synthesis of (Z,Z)-11,13-hexadienal, a Female Sex Pheromone of the Navel Orangeworm, Amyelosis transitella, (Lepidoptera: Pyralidae)” Journal of Chemical Ecology, 6,221-228, 1980). U.S. Pat. Nos. 4,198,533 and 4,228,093 describe similar seven or more reaction step methods. Some of the problems faced by industry in the process of making pheromones, include use of toxic reagents, lack of available refined starting materials on the market, and inefficiencies in the processes. There is need for new and better methods for synthesizing the navel orangeworm pheromones.
To the best of knowledge known at the time of the patent application, the improved methods herein for creating a synthetic composition of the navel orangeworm pheromone for use in pest management have not been described.